Adds asynchronous thread management

- Posix Thread and Gevent support
Moves imports
Merge pull request #497 from lukecampbell/async

Adds asynchronous thread management
Starting work on thread pool

- More Tests
- Successful AsyncResult for multithreaded code
Primitive thread-pool-ish thing
Do not clean file systems when a server container has started in the case of pycc and launches
A functional thread pool
Comments and removes a print statement
Merge pull request #499 from jamie-cyber1/fix_datasets_xml

Do not clean file systems when a server container has started in the cas...
Adds thread-exit synchronization

Big Note: If a timeout is placed on synchronizing the exiting of the pthreads,
and it is exceeded, the pool becomes inconsistent. I use a SystemError instead
of a timeout, to force a fast-fail.
Fixes comments and docstrings
Started work on the threading lib
Finishes porting _threading module, untested
Removes leading underscore in threading.py
Merge pull request #503 from lukecampbell/threads

Gevent and Threading, working together
Updates the threadpool to use the Queue from threading
Merge pull request #505 from lukecampbell/threads

Updates the threadpool to use the Queue from threading
Filesystem changes
Merge pull request #506 from lukecampbell/fs

Filesystem changes
Merge remote-tracking branch 'origin/master' into M153